Locking mechanism especially for the control of electrical disconnection apparatuses

ABSTRACT

A mobile unit carries a movable switch at one end and longitudinally spaced, transverse shafts to one side thereof. One shaft is spring biased to the upper end of a vertical guide slot while the other shaft rides on a push button, spring biased, sliding control piece. A spring biased locking plate carrying a window, cooperates with a spring biased, oscillating lever to receive a stop during switch closing position while a projection on the same oscillating lever locks up the sliding control piece. Tilting of the spring biased locking plate releases the switch contacts and the sliding control piece.

United States Patent [72] Inventors Jean Morin;

Gerard Desperrler, both oi Saint-Marcellin, France 29,582

Apr. 17, 1970 Aug. 31, 1971 So clete D'Appareillage Electrique Saparel Saint-Marcellin, France [Zl App]. No. [22] Filed [45] Patented (73] Assignee [54] LOCKING MECHANISM ESPECIALLY EOR THE CONTROL OF ELECTRICAL DISCONNECTION R,39,61.42, 153, 1 9 PB 1 Primary Examiner-J. R. Scott Attorney-Sughrue, Rothwell, Mion, Zinn and Macpeak ABSTRACT: A mobile unit carries a movable switch at one end and longitudinally spaced, transverse shafts to one side thereof. One shaft is spring biased to the upper end of a vertical guide slot while the other shaft rides on a push button, spring biased, sliding control piece. A spring biased locking plate carrying a window, cooperates with a spring biased, oscillating lever to receive a stop during switch closing position while a projection on the same oscillating lever locks up the sliding control piece. Tilting of the spring biased locking plate releases the switch contacts and the sliding control piece.

PATENTEU Ausal l9?! 3502.673

sum 1 [IF 2 22 INVENTORY JEAN MOIQ l/Y GERARD DESPERR/ER Sujkfld {29M "NR1, BY 2 M ATTORNEYS LOCKING MECHANISM ESPECIALLY FOR THE CONTROL OF ELECTRICAL DISCONNECTION APPARATUSES BACKGROUND OF THE INVENTION Description of the Prior Art 7 Automatic electrical switches involve an assembly of parts interconnected mechanically, and generally called an interlock mechanism, whose function is:

to permit the establishment of an electrical circuit by acting on one or more contact elements; to maintain the continuity of the electrical circuit by locking the assembly of moving pieces in the closing position when the arming operation is terminated; to automatically interrupt the continuity of the electrical circuit when the latters state is no longer in determined operating condition; to permit an operator to open contacts by acting upon an appropriate operating member of the mechanism. Numerous versions of such locks are already known. They generally employ one or more well-known mechanical systems, called universal or baIl-and-socket joints-simple systems which, however, require relatively large number of parts and which involve numerous articulations. Because of their weight and the friction involved, these elements reduce the acceleration of the movements, they increase the duration of separation of the contacts and they consequently reduce the performance of apparatuses thus equipped, while making their construction generally expensive.

SUMMARY OF THE INVENTION This invention relates to an interlock mechanism which can be used especially for controlling electrical cutoff apparatuses and which does not entail these inconveniences.

It is characterized by the fact that it involves, on the one hand, a mobile unit equipped with at least one contact piece capable of cooperating with a fixed contact piece and two lugs, the first of which can slide on a fixed slide-bar and tends to be held at one end of that bar due to the action of a spring when the contacts are in the open position, and whose second lug cooperates, without being connected to it, with a catch of a sliding control piece. On the other hand, a lever oscillates around a fixed axis of said lever and is subjected to the action of a spring tending to engage a projection in the window of the control piece and a stop of said lever in a window of a locking plate oscillating around a fixed axis. The members are arranged in such a way that when one lowers the control piece, its catch will, on the one hand, be supported on the second lug of the mobile unit so as to lower the latter essentially parallel to itself until its first lug essentially reaches the other end of the slide-bar. n the other hand, the oscillating lever tips due to the fact that its projection can engage in the window of the control piece and its stop in the window of the locking plate, which inclines due to the action of a spring so as to lock said stop in said window. A shoulder of said lever is then placed above the first lug of the mobile unit so as to keep it at the bottom of the slide-bar, which locks said mobile unit, since, when one allows the control piece to rise, the mobile unit turns around its first lug at the bottom of the slide-bar. Further, the second lug escapes the catch of the control piece. The mobile unit then is able to rotate under the action of its associated spring until its contact piece is applied upon the fixed contact piece.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1-6 represent by way of example one possible version of a locking mechanism according to the invention.

FIG. 1 is a schematic cross section view along axis AA in FIG. 2, and schematically represents the various elements of the lock and the operating members in the "released" state.

FIG. 2 is a schematic, partial side view of the device according to FIG. 1.

FIG. 3 is a similar view to that of FIG. 1, showing the respective position of the various elements at the end of the first arming phase.

FIG. 4 is a similar view, showing the position of the elements at the end of the second arming phase, corresponding to the locking of the assembly in the interlocked" state.

FIG. 5 shows the displacements of the contact-carrier unit during the automatic operation of the mechanism.

FIG. 6 shows the position of the elements at the beginning of the voluntary and manual release of the mechanism.

DESCRIPTION OF THE PREFERRED EMBODIMENT An oscillating lever 1, for example, made of molded material, can pivot around an axis 2 between two cheeks 3 and 4 and tends to move in the counterclockwise direction due to the ac-- tion of a spring 5.

On either side of the cheeks, contact-carriers, symbolized by the lines 6 and 7, are joined to each other by means of two transverse shafts 8 and 9. Shaft 9 is guided and can slide in two guides 10 and 11 which are made in the cheeks; two springs 12 and 13, attached, for example, to respective cheeks 3 and 4,,

tend to draw the contact-carrier assembly upward in the figure. V v

In the released position, axis 9 is below a catch 14 of a control member 15 which itself is moved upward in the figure by a recovery spring 16.

Finally, the mechanism involves a locking plate 17, pivoting around an axis 18 and which tends to move against a stop 20 by the action of a compression spring 1Q.

In the position according to FIG. 1, axis 8, which is in the upper portion of the slide 11, rests on a side 30 of the oscillating lever 1 which keeps it in the position shown; in this position, an upper stop 25 of this lever raises the right end of the locking plate 17 and a lower projection 22 of said lever is kept away from the operating member 15.

Referring now to FIGS. 3 and 4, we can see that the transition from the released" to the locked position is accomplished in the following manner:

When one drives control member 15 in the direction of arrow F, this produces-through catch 14 and shaft 9the translation of the moving contact-carrier unit 6, 7, guided by its shaft 8 in slide guides 10, 1 1, until axis 8 butts into the bottom of the slides. When the operating member and the contact-carrier are in this extreme position, the side 30 of the oscillating lever l escapes shaft 8 and the lever tips, due to the action of spring 5, until its shoulder 24 is placed above axis 8, as shown in FIG. 3. In this position, the stop 25 of the lever is placed in the window 21 of plate 17 where it is locked by the tipping of this plate due to the action of spring 19. At the same time, the lower projection 22 of the lever is placed in a window 23 of the operating member- 15.

When one relaxes the pressure on the operating member 15, the latter goes back up due to the action of recovery spring 16. The contact-carrier 6 (7) likewise goes back up due to the action of springs 12 (13) until its shaft 8 is supported on the shoulder 24 of lever l, the latter being immobilized due to the fact that its stop 25 rests on the edge of window 21 of plate 17.

Shaft 8 then is fixed and serves as axis of rotation for the contact-carrier unit. Operating member 15 continues its rising movement, and the contact-carrier unit pivots around shaft 8, and it arrives at the moment when shaft 9 abruptly escapes from catch 14, thusbringing about the rapid closing of the mobile contacts 26 upon the fixed contacts 27, something which is accomplishedindependently of operating member 15. The upward movement of the operating member 15 is stopped when its window 23 bumps against the projection 22 of oscillating lever 1, which causes the lockto be locked.

It must be noted that the pressure between the fixed contact piece 27 and the mobile contact piece 26 is assured by recovery springs 12, 13 of the mobile unit.

In the locked position, oscillating lever 1 is subjected, on the one hand, to a force exerted by recovery springs 12, 13, throughv shaft 8, -upon shoulder 24 and which tends to bring of just a single one of them, for example, spring 5, with the other ones being initially adjusted), the resultant couple, to which oscillating lever 1 is subjected, may be reduced as much as one desires, so that a minor effort, exerted by spring 19, suffices for plate 17 to lock the assembly. It also suffices to exercise the very small force F upon this plate 17 (FIGS. 4 and 5) to unlock the lock.

This opposing force F may be exercised by any means, such as, for example, the action of a thermostatic leaf, a current.

relay, a voltage relay, a mechanical member, etc. It rotates the plate 17 around its axis 18 and releases the oscillating lever 1 which, subjected to the above mentioned resultant couple,

pivots around axis 2 in the clockwise direction, thus releasing at the same time shaft 8 and operating member 15.

With shaft 8 having been released, the mobile contact-carrier unit 6, 7 goes back up and pivots due to the action of recovery springs 12, 13, which brings about the separation of contacts 26, 27 in the manner indicated below: a

. At first (FIG. 5), the contact-carrier unit 6, 7 goes up practically parallel to itself over a short distance d, thus bringing about the establishment of a disconnect are between contacts 26, 27. Then the contact, carrier 6, 7, along its way, runs into fixed stop 20 which, for example, is made in one piece with the cheeks, thus constituting a point of rotation for the mobile unit. The position of this stop 28 is such that, on the one hand, the displacement of the mobile contact 26 speeds up and has a great amplitude, although the points of application of the recovery forces move very little and, on the other hand, shaft 9, destined for the arming of the lock, resumes its place along the operating member 15.

Projection 22 being disengaged from window 23, the operating member can also go back up due to the action of spring 16 and return to the position shown in FIG. 1.

There are two special cases that must be considered:

In the first case, operating member 15 is free, that is to say, it is not voluntarily held in the position where it was in FIG 4; in this case, during the release of the oscillating lever 1 by plate 17, the mobile contact-carrier unit 6, 7 and the operating member 15 moves simultaneously and shaft 9 directly resumes the position which it had according to FIG. 1, that is to say, under the catch 14.

In the second case, the operating member 15 is voluntarily kept in the position in'which it was according to FIG. 4; in this case, during the release of oscillating lever l, the mobile unit 6, 7 moves along, while the operating lever 15 remains motionless in the position shown in FIG. 5 and axis 9 is above catch 14. When the stress on the operating member is eliminated, the latter is set in motion due to the action of the recovery spring 16 which is then strongly compressed, while springs 12, 13 were practically released, so that catch 14 can overcome the resistance offered to its passage by shaft 9 and can move into position above the latter. It is also possible to make catch 14 easily overcome during the upward movement of the operating member and to cause it to be fixed during its descent.

One particular advantage of the invention will be described below with reference to FIG. 4. If an automatic switch, equipped with the mechanisms described above, undergoes an overload so thatin spite of the rapidity of the unlocking of the locka circuit is established between contacts 26, 27, the operating member 15 remains in the position shown in FIG. 4 and therefore indicated that the switch circuit is not cut off. In effect, as a result of this circuit establishment between the contacts, the contact-carrier becomes fixed and rigid so that the action of recovery springs 12, 13 is no longer transmitted by shaft 8 to oscillating lever 1. The latter now is subjected only to the action of springs 5 and 16 which then tend to make FIGS. 3, 4, and6. In theabove, the operating member has been used onlyto guarantee the arming of thelock, but it can also serve to unlockit. It thus plays a double role. In FIG. 2,

the movement of the operating member, in contact with shaft.

9, is subjected to a drive push effort and is limited when shaft 8 bumps into the bottom of slides 10, 11. This limitation of movement of the operating member 15 no longer exists when locked as shown in FIG. 4, since shaft 9 then escapes catch 14. Referring now to FIG. 6, if one again pushes the operating member, the latter, by means of face 29 of window 23, transmits a force on the projection 22 of oscillating lever 1. This force creates a supplementary couple (torque) applied to the lever which is added to the couple created bysprings 12, 13 and causes the unlocking of the lever which escapes the plate 17, and its displacement in the clockwise direction, .thus releasing the mobile contactscarrier unit.

In summary, the lockingdevice according to the invention thus offers the following advantages:

the contact-carrier is not mechanically connected ina fixed fashion to the lock assembly and due to this fact it can move rapidly and independently of the other pieces constituting the mechanisms; the mobile contacts, at a certain moment, become independent of the operating member and then establish electrical circuits abruptly and independently of the operator; the pressure of the contacts is guaranteed by the recovery springs of the mobile units; the oscillating lever is subjected to an assembly of opposing couples; a r the resultant couple applied to the lever can easily be regulated at a relatively low value, and hence offers very great sensitivity for theunlocking of the lock; the movement of the contacts involves one translation and one rotation; the opening distance is very large whereas the other elements of the lock move, very little, hence fast contact openings speed; v I the response time of the lock is very short; the position of the operating member indicates the position of the contacts in the apparatus; I the operating member can successively be used for both locking and release of thelock. The invention is by no means limited to those of its possible versions which have just been described'and represented here by way of example but it includes all variants responding to the definition to be found in the claim. In particular, it is not mandatory for the lock to have the symmetrical form shown in FIG. 2. The lock according to the invention may of course be used in any automatic electrical apparatus as a circuit breaker or differential switch, regardless of what the number of poles may be.

What is claimed is:

1. In combination, an electrical disconnect switch and an interlock mechanism comprising: a fixed contact, a mobile unit including a movable contact and two longitudinally spaced transversely extending shafts fixed thereto, a fixed guide receiving one shaft, a first biasing spring for biasing said first shaft toward one end of said guide for maintaining said contacts open, a sliding control piece including a catch for operatively contacting said second shaft, and a window therein, a lever mounted for oscillation about a fixed axis and including a stop and a projection, a locking plate mounted for oscillation about a fixed axis and including a window therein, a second spring for biasing said lever projection into engagement with said window of said control piece and for biasing said lever stop into engagement with said window in said locking plate, whereby sliding said control piece in one direction causes said catch to contact said second shaft of said mobile unit to lower the latter essentially parallel to itself until said first shaft reaches the other end of said guide, said oscillating lever tipping when its projection engages the window of the control piece and its stop engages the window of the locking plate, said inclination due to the action of said biasing spring tending to lock said stop in its window, and said apparatus further including a shoulder carried by said lever and movable into position above said first shaft to maintain said shaft at the bottom of said slot for locating said mobile unit during sliding of said control piece in said first direction, and whereby, during movement of the said control piece in a reverse direction, said mobile unit pivots about its first shaft at the bottom of said guide allowing said second shaft to escape the catch of said control piece, whereby said mobile unit is then capable of rotating at high speed to cause said movable and stationary contacts to abruptly close.

2. The mechanism as claimed in claim 1, wherein said fixed guide comprises laterally spaced vertical slots, said control piece is mounted for reciprocation parallel to the longitudinal axis of said guide slots, said locking plate is mounted for oscillation about a fixed horizontal axis above said guide slots and on the side opposite said sliding control piece, and a fixed stop limits oscillation of said guide plate in a direction away from said oscillating lever.

3. The mechanism as claimed in claim 2, wherein said oscillating lever is mounted for oscillation about a horizontal axis which lies below said guide slots and intermediate said guide slots and said sliding control piece, said second spring is coupled to said lever intermediate of said guide slots and said horizontal pivot axis for said lever, said projection is carried on one said lever to one side of said horizontal pivot axis and said stop is carried on the opposite side thereof. 

1. In combination, an electrical disconnect switch and an interlock mechanism comprising: a fixed contact, a mobile unit including a movable contact and two longitudinally spaced transversely extending shafts fixed thereto, a fixed guide receiving one shaft, a first biasing spring for biasing said first shaft toward one end of said guide for maintaining said contacts open, a sliding control piece including a catch for operatively contacting said second shaft, and a window therein, a lever mounted for oscillation about a fixed axis and including a stop and a projection, a locking plate mounted for oscillation about a fixed axis and including a window therein, a second spring for biasing said lever projection into engagement with said window of said control piece and for biasing said lever stop into engagement with said window in said locking plate, whereby sliding said control piece in one direction causes said catch to contact said second shaft of said mobile unit to lower the latter essentially parallel to itself until said first shaft reaches the other end of said guide, said oscillating lever tipping when its projection engages the window of the control piece and its stop engages the window of the locking plate, said inclination due to the action of said biasing spring tending to lock said stop in its window, and said apparatus further including a shoulder carried by said lever and movable into position above said first shaft to maintain said shaft at the bottom of said slot for locating said mobile unit during sliding of said control piece in said first direction, and whereby, during movement of the said control piece in a reverse direction, said mobile unit pivots about its first shaft at the bottom of said guide allowing said second shaft to escape the catch of said control piece, whereby said mobile unit is then capable of rotating at high speed to cause said movable and stationary contacts to abruptly close.
 2. The mechanism as claimed in claim 1, wherein said fixed guide comprises laterally spaced vertical slots, said control piece is mounted for reciprocation parallel to the longitudinal axis of said guide slots, said locking plate is mounted for oscillation about a fixed horizontal axis above said guide slots and on the side opposite said sliding control piece, and a fixed stop limits oscillation of said guide plate in a direction away from said oscillating lever.
 3. The mechanism as claimed in claim 2, wherein said oscillating lever is mounted for oscillation about a horizontal axis which lies below said guide slots and intermediate said guide slots and said sliding control piece, said second spring is coupled to said lever intermediate of said guide slots and said horizontal pivot axis for said lever, said projection is carried on one said lever to one side of said horizontal pivot axis and said stop is carried on the opposite side thereof. 